Glass spout bowls are generally provided on the end of an elongated forehearth channel where molten glass is heated and conveyed to the bowl for the formation of gobs of glass which are then directed to several molds in a modern glassware forming machine. The bowl is generally mounted on fixed structure at the discharge end of the glass forehearth and a feeder mechanism is provided in the bowl to issue glass gobs from orifices defined in the lower portion of the feeder bowl. A typical feeder mechanism includes one or more vertically reciprocable plungers operated in cooperation with shears and other feeder components in order to control the manner in which the gobs are formed for gravity feed to the various sections of a typical glassware forming machine.
A typical feeder may include one or more plungers, each of which may be axially aligned above an associated orifice in the bottom of the spout bowl and through which orifice the molten glass is adapted to issue. The gob is sheared by reciprocating shear blades and the operation of the shears and plungers is synchronized with the operation of the glassware forming machine so that these mechanisms operate cyclically in accordance with a predetermined timing sequence.
When the glass flow is to be shut down for some reason, and the plungers are no longer reciprocated to form glass gobs, conventional practice provides for the tube inside the spout bowl to be seated on an annular surface defined for this purpose inside the bowl in order that no more molten glass can issue from the orifices in an orifice plate structure provided in the lower portion of the feeder bowl. Conventional practice also calls for the rotation of such a tube continuously during normal operation of the feeder bowl with the distance between the lower end of the tube and the above mentioned annular seat defined in the spout bowl is kept at a predetermined spacing for optimum flow of glass to the reciprocating plungers.
The above mentioned copending patent application deals with an improved plunger operating mechanism wherein a reversible electric motor is connected to drive a plunger support in a cyclically reciprocating manner, and wherein a programmable control means operably coupled to the motor causes such oscillation between predetermined limits and according to a predetermined motion profile. The support bracket is cantilevered so that the reversible motor operates between fixed structure associated with the frame at the discharge end of the glass forehearth. The plunger support bracket mounting means includes the capability for adjustably positioning the plungers relative to the spout bowl (itself attached to the front end of the forehearth) so that the plungers can be aligned with the orifices in the orifice plate itself.
Although refractory tubes have been provided in spout bowl surrounding vertically reciprocating plungers for the general purpose as stated above, the present invention relates to an improved mounting structure for such refractory tube in a spout bowl environment. The refractory tube is so constructed and arranged that it can be removed for replacement and repair by the refractory tubes of different size in the same support mechanism. Furthermore, the support mechanism itself is more efficiently designed to accommodate adjustments in a horizontal plane with the same results as achieved for such adjustments of the plunger support mechanism as described above.
Another advantage to the refractory tube support mechanism described herein relates to its uniquely balanced construction such that a relatively small electric stepping motor can be utilized to raise and to lower the refractory tube and said support mechanism. A digital display is provided to facilitate setting up the feeder mechanism following a shut down. All of the aforementioned advantages are realized in a refractory tube support mechanism which also provides for rotation of the tube itself during normal operation of the feeder.
Finally, the tube support mechanism is mounted on a single vertically extending pivot post such that the balanced support frame (after removal of the refractory tube chucking system) can be swung to either side in order to facilitate working on the spout bowl itself or on the refractory tube support mechanism. The refractory tube is so arranged in its chucking mechanism that the tube can be readily removed from its position inside the spout bowl with a minimum of time and effort required to disengage the chucking mechanism from the balanced frame while the frame is located in position over the spout bowl.